Kato, Card Master

Whenever you cast an instant or sorcery spell,
you may exile X cards from the bottom of your library, where X is the number equal to its mana
value. You may play cards exiled this way until
the end of your next turn.
When Kato, Card Master, deals combat damage
to a player, you may put any number of cards
from your hand on the bottom of your library.
—
"I didn't ask how big the room is, I cast fireball."